Especially with reference to hydraulic conduits for actuating subsea petroleum well drilling equipment, such as blowout preventers, it is known to provide an underwater non-destructive quick attachable and detachable or fast multiple connection between fluid conduits going to the blowout preventers, or other underwater remote actuated devices or functions, and subsea valve controlled fluid conduits going to the surface, where an operator can actuate surface devices for remote control of the subsea valves and associated functions. See, for example, the apparatus disclosed at pages 6144-6149 of the 1978-79 edition of the Composite Catalog of Oilfield Equipment and Services and the Catalog of Valve Control Company entitled "1978 Catalog BOP Control Systems" published by the Valvcon division of Hydril Co., and pages 4494-10 to 4494-18 of the 1970-71 issue of the Composite Catalog, and U.S. Pat. No. 3,701,549 to Koomey, De Vries, and Gilmore, 3,460,614 and 3,486,556 to Burgees, and 3,326,579 to Fowler, and the references therein to prior patents.
The fast multiple connections disclosed in the foregoing publications include a multi-ported socket to which one set of conduits is connected and a multi-ported plug releasably received and locked in the socket with the plug ports communicating with the socket ports in fluid tight relationship. Three forms of construction include conical, flat wedge, and cylindrical opposed surfaces of the plug and socket. The present invention relates particularly to the type employing cylindrical surfaces although it can also be used with other types of construction, both tapered and non-tapered plugs and sockets, with both flat and non-flat surfaces, and with ports in bodies other than plugs and sockets.
Flat plane, cylindrical, and conical surface have in common that they are generated by motion of a straight line at a constant distance from an axis, the line being parallel to the axis the case of a cylinder and plane, the radius relative to the axis being infinite in the case of a plane.
It is more difficult to effect seals between the ports of cylindrical or parallel-sided box type plug and socket constructions than between the ports of conical or flat wedge type plug and socket constructions, for in non-tapered constructions, the protuberant seal means on either the plug or socket is apt to be damaged when the connection is made up. Also, it is difficult with cylindrical or box types of construction to provide back-up metal-to-metal seals for the soft sealing means.
According to the Fowler patent mentioned above, there is provided a connection of the cylindrial type wherein seawater is excluded from the ports by protuberant soft seals extending around the plug above and below the ports, and intercommunication between the several ports in the plug and intercommunication between the several ports in the socket is prevented by a conduit tube extending from each plug port telescopically into a respective one of the socket ports. Alignment pins and slots bring the plug and socket ports into registry. Should the conduit tube actuator fail to withdraw the conduit tubes when it is desired to break the connection, there is no way to separate the plug and socket. The conduit tube in each case is mechanically propelled from the plug into the socket when the connection is made up, and each conduit tube is provided with protuberant O-rings to form a straddle pack-off between the plug and socket. In addition, pressurized fluent plastic seals are provided around each conduit tube and between the plug and socket. It will be seen that there is no metal-to-metal back-up seal for the seal rings, O-rings, or plastic sealant.